<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>浮动demo1</title>

    <style>
        * {
            padding: 0;
            margin: 0;
        }

        a {
            color: #fff;
            font-size: 16px;
            text-decoration: none;
            line-height: 50px;
            display: block;
        }

        .left a:hover {
            color: orange;
        }

        ul {
            list-style: none;
            margin: 50px 30px;
        }

        li {
            height: 50px;
        }

        .box {
            width: 1200px;
            height: 600px;
            margin: 100px auto;
        }

        .left {
            float: left;
            width: 30%;
            height: 100%;
            background-color: gray;
        }

        .right {
            float: left;
            width: 70%;
            height: 100%;
            background-color: seagreen;
        }
    </style>

</head>
<body>
    
    <div class="box">
        <div class="left">
            <ul>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
                <li><a href="#">标签</a></li>
            </ul>
        </div>
        <div class="right"></div>
    </div>

</body>
</html>